Magnet roll, method of manufacturing the magnet roll, and electronic equipment using the magnet roll

ABSTRACT

A magnet roller includes a rotary sleeve having a given systematic pattern on the outer surface of the sleeve and a magnet provided in the sleeve. This structure transfers toner uniformly along the outer surface of the sleeve. A printer, for instance, employing this magnet roller can print a fine copy.

This application is a U.S. National Phase application of PCTInternational application PCT/JP01/09088.

1. Technical Field

The present invention relates to a magnet roller to be employed inelectronic apparatuses such as a copying machine, printer, facsimile,and a method of manufacturing the same magnet roller. It also relates toelectronic apparatuses employing the same magnet roller.

2. Background Art

A magnet roller comprises a rotary sleeve and a magnet disposed in thesleeve. On the outer surface of the sleeve, numerous peaks and valleysare formed, and these peaks and valleys contribute to transferringtoner. Recently, the market has demanded that the peaks and valleys bemore closely formed. To be more specific, a copying machine produces acopy of higher resolution, thus the peaks and valleys more closelyformed on the outer surface of the sleeve could enlarge an outer surfacearea, thereby transferring a greater amount of toner. However, even ifthe peaks and valleys are formed more closely on the outer surface ofthe sleeve, it does not directly result in printing a higher resolutioncopy.

This problem is caused by the following reason. In prior art, peaks andvalleys are formed by sand blasting. When the peaks and valleys formedby the sand blasting are required to be more closely formed, aprocessing time of the sand blasting should be prolonged or a strongerinjection pressure should be used by the sand blasting. However, if theprocess time is prolonged or the stronger injection pressure is applied,it could curve the sleeve per se. Although peaks and valleys are formedmore closely on the outer surface of the sleeve, the curved sleeveprevents the copying machine from printing a copy of higher resolution.

SUMMARY OF THE INVENTION

The present invention addresses the problem discussed above and aims toprovide a magnet roller which allows the apparatus employing the magnetroller to print a copy of higher resolution, a method of manufacturingthe same magnet roller and electronic apparatuses using the same magnetroller.

The magnet roller of the present invention comprises a rotary sleeve anda magnet disposed in the sleeve. On the outer surface of the sleeve, agiven systematic pattern is formed. Since the predetermined systematicpattern is formed, toner can be transferred uniformly along the outersurface of the sleeve, so that a copy of higher resolution can beprinted.

The method of manufacturing the magnet roller of the present inventionincludes a step of forming a predetermined systematic pattern by etchingor laser processing on the outer surface of the rotary sleeve. This stepis carried out during the manufacturing of the magnet roller whichincludes the rotary sleeve and the magnet disposed in the sleeve. Thismethod allows to form a predetermined systematic pattern with ease onthe outer surface of the sleeve.

The electronic apparatuses of the present invention include the magnetroller that transfers fluid or powder. The magnet roller comprises therotary sleeve and the magnet disposed in the sleeve, and a predeterminedsystematic pattern is formed on the outer surface of the sleeve. Thisstructure allows the apparatuses to transfer fluid or powderappropriately, thereby printing a copy of higher resolution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a magnet roller in accordance with a firstexemplary embodiment of the present invention.

FIG. 2 is a partial sectional view of a front view of the magnet rollerin accordance with the first embodiment.

FIG. 3 is an enlarged front view of the sleeve of the magnet rollershown in FIG. 2.

FIG. 4 is an enlarged front view of a sleeve of a magnet roller inaccordance with another embodiment of the present invention.

FIG. 5 is an enlarged front view of a sleeve of a magnet roller inaccordance with still another embodiment of the present invention.

FIG. 6 is an enlarged front view of a sleeve of a magnet roller inaccordance with further another embodiment of the present invention.

FIG. 7 is an enlarged front view of a sleeve of a magnet roller inaccordance with still further another embodiment of the presentinvention.

FIG. 8 is an enlarged front view of a sleeve of a magnet roller inaccordance with another embodiment of the present invention.

FIGS. 9 and 10 are front views illustrating a method of manufacturing amagnet roller in accordance with a second exemplary embodiment of thepresent invention.

FIG. 11 is a front view illustrating another embodiment of the method ofmanufacturing a magnet roller of the present invention.

FIG. 12 is a front view illustrating still another embodiment of themethod of manufacturing a magnet roller of the present invention.

FIG. 13 is a perspective view illustrating further another embodiment ofthe method of manufacturing a magnet roller of the present invention.

FIG. 14 is a sectional view of an electronic apparatus in accordancewith a third exemplary embodiment of the present invention.

PREFERRED EMBODIMENTS OF THE INVENTION

Exemplary embodiments of the present invention are demonstratedhereinafter with reference to the accompanying drawings.

First Exemplary Embodiments

FIG. 1 is a sectional view of a magnet roller in accordance with thefirst exemplary embodiment of the present invention, and FIG. 2 is apartial sectional view of a front view of the magnet roller. In FIG. 1,cylindrical sleeve 1 is made of aluminum or stainless steel. Both endsof sleeve 1 are open, and flange 2, 3 are fixed to the respectiveopenings. Shaft 4 extends through through-hole 2 a of flange 2. Theright-side end of shaft 4 is supported by bearing 5 inside flange 3.Shaft 4 is also supported by bearing 6 inside flange 2.

On the outer surface of shaft 4 housed in sleeve 1, magnet 7 is rigidlymounted. In an electronic apparatus such as a copying machine, shaft 3 aof flange 3 is rotated with shaft 4 being fixed. This rotation entailssleeve 1 fixed to flange 3 to rotate. In other words, with shaft 4 beingfixed, sleeve 1 is rotatable.

Next, sleeve 1 is detailed. As shown in FIG. 2, predetermined systematicpattern 8 is formed on the outer surface of sleeve 1. Several examplesof pattern 8 are shown in FIG. 3 through FIG. 8. Pattern 8 shown in FIG.3 is formed of aggregate of a plurality of linear recesses 9, in otherwords, linear recesses 9 are systematically arranged. Since such kind ofsystematic pattern 8 is formed on the outer surface of sleeve 1,recesses 9 are clogged with toner, and the toner is thus transferredwhen sleeve 1 rotates.

Linear recesses 9 are suitable for being formed by etching or laser,which can form recesses 9 keeping a regular pattern with an enoughdepth. The toner thus can be definitely transferred. Meanwhile, when agreater amount of toner needs to be transferred, a number of recesses 9should be increased or the depth of recesses 9 should be deepened.Therefore, a manufacturer of this magnet roller prepares a plurality ofpatterns differing in number, placement, depth of recesses 9, so thatthe manufacturer selects one of the patterns upon request from a userand then forms the pattern by etching or laser on sleeve 1.

Pattern 8 shown in FIG. 4 is formed of aggregate of a plurality ofcurved recesses 10. Pattern 8 shown in FIG. 5 is formed of aggregate ofa plurality of recesses outlining a triangular shape 11. Pattern 8 shownin FIG. 6 is formed of aggregate of a plurality of recesses outliningquadrangle shape 12. Pattern 8 shown in FIG. 7 is formed of aggregate ofa plurality of recesses outlining pentagonal shape 13. Pattern 8 shownin FIG. 8 is formed of aggregate of a plurality of recesses outlininghexagonal shape 14. As such, a predetermined systematic pattern isformed on the outer surface of the sleeve.

A manufacturer of the magnet roller prepares various patterns, e.g., thepatterns shown in FIG. 3 through FIG. 8, and selects one of them uponrequest from a user. Then the selected pattern is formed on the sleeve.Thus an amount of toner requested by the user can be transferreduniformly and adequately. As a result, the magnet roller that prints acopy of higher resolution can be provided.

Second Exemplary Embodiment

FIG. 9 illustrates a method of manufacturing a magnet roller inaccordance with the second exemplary embodiment of the presentinvention, more particularly it illustrates a method of manufacturingsleeve 1 of the magnet roller. To be more specific, various patterns 8shown in FIG. 3 through FIG. 8 can be formed, for instance, by themethod illustrated in FIG. 9.

The method is detailed hereinafter. As shown in FIG. 9, both the ends ofsleeve 1 are held by holders 15, 16. Recessed holding sections 15 a, 16a are provided on the faces of holders 15, 16 opposite to each other,and sleeve 1 is inserted into holding sections 15 a, 16 a, so thatsleeve 1 is held. In other words, recesses are not formed on both theends inserted in holding sections 15 a, 16 a in the step of formingpattern 8. Both the ends thus do not have recesses, so that tonerneither attaches to the ends nor overflows advantageously from bothsides of sleeve 1.

Next, with sleeve held by holders 15 and 16, nozzle 17 ejects resist tothe outer surface of sleeve 1, moving along arrow-mark A as shown inFIG. 9. Then with nozzle 17 located on the right hand side of sleeve 1,holders 15 and 16 rotate by a given angle along arrow-mark B shown inFIG. 9, e.g., by 10 degrees. When the rotated angle is not more than 10degrees, though an outer diameter of sleeve 1 somewhat affects, theresist attaches to the outer surface correctly within an area of 10degrees even if the surface forms a cylinder. This mechanism is similarto the mechanism of printers, i.e., when a printer prints an image, anexact image can be reproduced even the drum has a curved surface.

Then in the condition where sleeve 1 rotates by 10 degrees, nozzle 17located on the right side as shown in FIG. 9 moves toward the oppositeside to arrow-mark A attaching resist to the outer surface at an area of10 degrees rotated. As such, holders 15, 16 are rotated 360 degrees atthe intervals of 10 degrees, thereby attaching resist to the outersurface of sleeve 1. This resist attaches to the areas of patterns 8shown in FIG. 3 through FIG. 8 except recesses 9 through 14 ofrespective patterns 8. In other words, resist does not attach to therecesses which form patterns 8.

To be more specific, the sections of any pattern 8 shown in FIG. 3through FIG. 8, where no resist attaches, are etched with etchingsolution, whereby any one of recesses 9 through recesses 14 are formed.In other words, in FIG. 9, resist attaches to the area except recesses 9of pattern 8 shown in FIG. 3 as discussed above. In the same manner,resist attaches to the area except recesses 10 of pattern 8 shown inFIG. 4, resist attaches to the area except recesses 11 of pattern 8shown in FIG. 5, resist attaches to the area except recesses 12 ofpattern 8 shown in FIG. 6, resist attaches to the area except recesses13 of pattern 8 shown in FIG. 7, and resist attaches to the area exceptrecesses 14 of pattern 8 shown in FIG. 8.

FIG. 10 illustrates another method of manufacturing the sleeve.According to this method, holders 15, 16 firstly rotate 360 degreesalong arrow-mark B. At this time, nozzle 17 stops at a place, and fromthere, attaches resist onto the outer surface of sleeve 1. When theholders have rotated 360 degrees, nozzle 17 moves a given distance alongarrow-mark A shown in FIG. 10. Then holders 15, 16 rotate again 360degrees along arrow-mark B. As such, resist attaches to the outersurface of sleeve 1 as if sleeve 1 were cut into thin round slices. Thismethod can also attach resist with ease to the sleeve for forming one ofpatterns 8 shown in FIG. 3 through FIG. 8.

FIG. 11 illustrates still another method which forms a continuous spiralrecess, which is different from the recesses shown in FIG. 3 throughFIG. 8, on the outer surface of sleeve 1. This pattern allows the magnetroller to move toner continuously, for instance, from left to right, forsupplying. Spiral pattern 8 shown in FIG. 11 is formed by the followingmethod.

First, nozzle 17 moves continuously along arrow-mark A with sleeve 1rotating along arrow-mark B shown in FIG. 11, so that resist 18 attachesto sleeve 1 for drawing a spiral pattern. After this, etching isprovided, so that recesses are formed at the places where no resistattaches. As a result, pattern 8 of a continuous spiral recess iscompleted.

FIG. 12 illustrates further another method which forms a pattern inwhich spiral patterns are crossed each other from both sides. In thiscase, firstly, attach resist 18 to sleeve 1 as shown in FIG. 11, thenmove nozzle 17 along arrow-mark C opposite to arrow-mark A in FIG. 11with holders 15, 16 rotating along arrow-mark B continuously. Resist isthus attached to the outer surface of sleeve 1 before etching is carriedout. As a result, pattern 8 of spiral recesses crossed each other fromboth sides is formed on the outer surface of sleeve 1.

FIG. 13 illustrates a method of attaching resist 18 correctly to theouter surface of sleeve 1 shown in FIG. 9 through FIG. 12. Sleeve 1 doesnot always have an even outer diameter longitudinally. When resist 18attaches to such a sleeve continuously as shown in FIG. 9 through FIG.12, there happens inconvenience in the continuity of resist patterns dueto the presence of sections having a greater diameter and a smallerdiameter. To be more specific, a resist pattern is broken or becomesthick at some places. To avoid this inconvenience, the method shown inFIG. 13 uses laser measuring instrument 19 for measuring the outerdiameter of sleeve 1 in advance. Then nozzle 17 ejects resist based onthe measurement. This method can prevent the continuity of the resistpatterns from being broken or the resist from being overlaid due to thedifference in outer diameter in the longitudinal direction. When anyones of recesses 9 through recesses 14 are formed by laser, the outerdiameter of the sleeve is measured in advance with laser measuringinstrument 19. Then laser process is carried out based on themeasurement, so that better recesses can be formed.

Third Exemplary Embodiment

FIG. 14 is a sectional view of a printer as an example of electronicapparatuses in accordance with the third embodiment. This printerincludes the sleeve, on which one of the patterns shown in FIG. 3through FIG. 8, FIG. 11 and FIG. 12 is formed.

This printer does not so much differ from conventional ones, thus thedescription thereof is simply made. In FIG. 14, laser generator 21outputs laser responsive to image information, and the laser reproducesthe image information on the outer surface of photo conductor drum 20.On the reproduced image, toner 23 is attached by developer 22. Inactual, container 24 of developer 22 contains toner 23, and sleeve 1rotates along arrow-mark A to transfer toner 23. Toner 23 is transferredaccording to a predetermined systematic pattern 8 shown in one of FIG. 3through FIG. 8, FIG. 11 or FIG. 12.

To be more specific, the toner is accommodated in the recesses ofpattern 8, so that the toner is transferred, and the toner attaches onlyto the image reproduced on photo conductor drum 20. At printing section25, the attached toner is transcribed onto paper 26 (an example of printmedia) transferred by transferring means 27.

In the present invention, as discussed above, one of the predeterminedsystematic patterns as shown in FIG. 3 through FIG. 8, FIG. 11 and FIG.12, i.e., an adequately calculated number of recesses per unit area, isformed on the outer surface of sleeve 1. The toner is accommodated inthe recesses, and transcribed onto paper 26. Therefore, an image can becopied at printing section 25 properly onto paper 26 without unevenness.

As discussed above, the present invention provides a predeterminedsystematic pattern on an outer surface of a sleeve, so that the fullcircumference of the outer surface can transfer toner uniformly. As aresult, a fine copy is obtainable.

The previous embodiments refer to powder such as toner to be transferredby the magnet roller; however, fluid such as ink can be transferred bythe magnet roller of the present invention with a similar advantage tothat of the previous embodiments.

INDUSTRIAL APPLICABILITY

The magnet roller of the present invention comprises a rotary sleeve,which includes a given systematic pattern formed on its outer surface,and a magnet disposed in the sleeve. Since the predetermined systematicpattern is formed on the outer surface of the sleeve, toner can betransferred uniformly along the outer surface of the sleeve. As aresult, a printer, for instance, including the magnet roller of thepresent invention, can produce a fine copy.

1. A method of manufacturing a magnet roller, the magnet rollercomprising: a rotary sleeve including a predetermined pattern having apredetermined number of recesses per unit area formed on an outersurface of the sleeve; and a magnet disposed in the sleeve, wherein themethod comprises the steps of: (a) depositing resist to the outersurface of the sleeve by printing, said resist prevented from beingdeposited on portions of said sleeve while, on other portions of saidsleeve, said resist is deposited so that said predetermined pattern isformed; and (b) performing etching to the outer surface for forming thepredetermined pattern on sections where no resist is printed as recessesin the rotary sleeve; (c) ejecting the resist from a nozzle to the outersurface of the sleeve in a manner corresponding to a shape of thepattern, so that the resist attaches to the outer surface of the sleevefor forming a predetermined shape, wherein the elected resist attachesto a first portion of the outer surface of the sleeve; (d) rotating thesleeve by a predetermined angle; (e) ejecting the resist from the nozzlefor attaching the resist to another portion of the outer surface of thesleeve; (f) rotating the sleeve by the predetermined angle; and (g)repeating steps (e) and (f) for attaching the resist to other portionsof the outer surface of the sleeve for drawing the predetermined shapewith the resist.
 2. The method of manufacturing a magnet roller of claim1, wherein the pattern is formed of aggregate of a plurality of linearrecesses.
 3. The method of manufacturing a magnet roller of claim 1,wherein the pattern is formed of aggregate of a plurality of curvedrecesses.
 4. The method of manufacturing a magnet roller of claim 1,wherein the pattern is formed of aggregate of a plurality of recessesoutlining at least one of triangular, quadrangular, pentagonal, andhexagonal shapes.
 5. The method of manufacturing a magnet roller ofclaim 1 comprising the steps of: forming a plurality of the patterns byetching; selecting one pattern from the patterns; and forming theselected pattern on the sleeve.
 6. The method of manufacturing a magnetroller of claim 1, wherein both ends of the sleeve are held by holders,and wherein the resist attaches to the outer surface of the sleeve fromthe nozzle with the sleeve being rotated by the holders.
 7. The methodof manufacturing a magnet roller of claim 6, wherein both the ends ofthe sleeve are held being inserted into respective holding sections ofthe holders.
 8. The method of manufacturing a magnet roller of claim 1,wherein an outer diameter of the sleeve is measured in advance, and theresist attaches to the outer surface of the sleeve from the nozzle basedon the measurement.
 9. The method of manufacturing a magnet roller ofclaim 1 comprising the steps of: ejecting the resist from the nozzle forattaching the resist to the outer surface of the sleeve with the nozzlemoving from a first end to a second end along a longitudinal directionof the sleeve; then rotating the sleeve by a predetermined angle, andejecting the resist from the nozzle for attaching the resist to theouter surface of the sleeve with the nozzle moving from the second endto the first end; then rotating the sleeve by the predetermined angle;and repeating these steps for attaching the resist to the outer surfaceof the sleeve for drawing a predetermined shape with the resist.
 10. Themethod of manufacturing a magnet roller of claim 9, wherein thepredetermined angle is not more than 10 degrees.
 11. The method ofmanufacturing a magnet roller of claim 1 comprising the steps of:ejecting the resist from the nozzle and attaching the resist to theouter surface of the sleeve with the nozzle being fixed and with thesleeve rotating 360 degrees; then moving the nozzle by a predetermineddistance with the nozzle being fixed; then ejecting the resist from thenozzle and attaching the resist to the outer surface of the sleeve withthe nozzle being fixed and with the sleeve rotating 360 degrees;repeating these steps for attaching the resist to the outer surface ofthe sleeve for drawing a predetermined shape with the resist.
 12. Themethod of manufacturing a magnet roller of claim 1, wherein the nozzleis moved from a first end to a second end along a longitudinal directionof the sleeve with the sleeve rotating continuously, and at a same time,the nozzle ejects the resist for attaching the resist to the outersurface of the sleeve to draw a continuous spiral shape with the resist.13. The method of manufacturing a magnet roller of claim 1, wherein thenozzle is further moved from the second end to the first end along alongitudinal direction of the sleeve with the sleeve rotatingcontinuously, and at a same time, the nozzle ejects the resist forattaching the resist to the outer surface of the sleeve to draw twocontinuous spiral shapes crossing each other.